SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad93ea2257a935eb389387d78750aef29daf433af3659188efd4669d5d6c9acf' 
  AND token = 'ZKyRi/5TT1T76TKX4FedsRnoB7QiEJQhzAdA62pwacM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}